Location. The mango grows to a good size and casts a dense shade, but the roots are not destructive. It requires full sun and perfect air drainage. It does best at the top or middle level of a slope. A windbreak should be provided in exposed areas. The trees may also need staking. In places where there is intense heat exposure, it needs the shade of other trees. In the garden or near the coast, plant against a south wall, or in an area surrounded by paving, to provide maximum heat. In the greenhouse, full light and free air movement are important to avoid disease.

Soils and Climate. Mangoes are adapted to many soil types, it will grow in almost any well-drained soil whether sandy, loam or clay, but avoid heavy, wet soils. A pH between 5.5 and 7.5 is preferred. They are somewhat tolerant of alkalinity. For good growth, mangoes need deep soil to accommodate their extensive root systems.

Mangoes can be grown on a wide range of soil types, from light sandy loams to red clay soils. Soil pH of 5.5 to 7.5 is preferred. Deep rich soils give the best production and fruit quality. Well drained soils are recommended. Moderately sloping sites are also recommended to prevent water logging. Deep soils without impermeable layers permit the development of deep taproots that aids in drought tolerance and wind resistance.

Mangoes grow best in seasonally wet/dry climate zones of the lowland tropics. A dry and/or cool season causes uniform floral initiation and tends to synchronize bloom and harvest. Mango does not attain a truly dormant state, but ceases growth at temperatures below 55-60oF. Temperatures below 60 or above 100°F at flowering can cause flower abortion, loss of pollen viability, and occasionally seedless fruit development (small).

Mangoes will grow from sea level to an elevation of about 1,500 feet, but mangoes are most productive below 1,200 feet. Mango is best adapted to hot, dry leeward areas that receive less than 60 inches of rainfall annually, but supplemental irrigation is desirable for highest yields in those areas. Trees have a high water requirement during fruit maturation. Anthracnose disease often destroys both flowers and developing fruits in humid, high-rainfall areas. Dry weather during the flowering period is best for fruit production. Wind can damage flowers and reduce yields. High winds can knock fruit off trees or cause scarring, since the fruit hang on long, pendulous floral branches at the periphery of the canopy. Mango trees should be protected from strong winds, but windbreaks that shade or compete with them should be avoided.

Planting Design, Training, Pruning. Prior to planting, field should be deeply ploughed, harrowed and leveled. Pits of proper size should be dug at appropriate distances and filled by adding sufficient quantity of farmyard manure. The seedlings to be planted should be procured from reliable nurseries few days before actual transplanting.

Time of planting: The best time for planting is when there is sufficient moisture in the atmosphere. In the area of heavy rainfall, the best time of planting mango is the end of the rainy season. In tracts where the rainfall is less, the planting can be done in the early part of the monsoon for better establishment. The planting should be done in the evening; otherwise if the day turns out to be unusually hot or dry, the plants may wither due to excessive loss of water. If the sky is overcast, planting can be done during daytime also

Planting distance: The planting distance varies according to variety, the fertility level of the soil and general growth conditions in the area. Where the growth is excessive, the distance should be 14 x 14 m, but in the dry zones where the growth is less, it can be regulated to about 10 x 10 m. For high density planting, the distance can be 5 x 3 or 5 x 2.5 or 3 x 2.5 or 2.5 x 2.5 m.

For increased early production, an extra tree may be planted in between mango placement and the center of a 200-square meter to be removed later when overcrowding is prevalent. Unfortunately, however, this extra tree is seldom removed due to Philippine cultural practices, which leads to overcrowding.

Size of pits: In locations where the soil is loamy and deep, pits of 0.5 x 0.5 x 0.5 m be dug at desired distances. However, in shallow and hill soils, the pits should at last be of 1 x 1 x 1 m size.

Filling of pits: The pits should be filled with the original soil mixed with 50 kg well rotten farmyard manure. In the top two-third portion, the proportion of the manure and soil may be kept as 1:3. In case of stony soils, it is better to remove all the stones from the excavated material and remaining soils should be mixed with soil scrapped from the left over area. The pits should invariably be filled before the rainy season, so that there is maximum settling down before the advent of heavy rainfall and much before planting.

Planting of mango seedling: The plant with its ball of earth intact should be taken out of the soil or pot. The plant can then be placed with the help of a planting board in the centre of the pit by excavating as much soil as necessary to accommodate the root-ball. The moist soil of the pit is then pressed all around the root ball to complete the planting process. A small basin is then made and the plant is properly watered. The planting should not be done so high as to expose the upper roots. It is always better to adjust it at the same height/depth at which it was in the seedling bag or the nursery bed.

Training and pruning: Normally, mango trees require very little pruning or training. However, the training of the plants in the initial stages is very essential to give them proper shape. In formative years, trees may be pruned to have one main trunk clear of branching up to about 3 ft. After that, they assume a desirable rounded canopy shape naturally. When the graft has branched too low, the process of training becomes very important. At least 75 cm of the main stem should be kept free from branching and the first leader/main branch may be allowed after that. The main branches should be spaced in such a way that they grow in different directions and are at least 20 to 25 cm apart, otherwise there are chances of breakage due to smaller crotch angles and heavy top. The branches which exhibit tendency of crossing and rubbing each other should be removed in the pencil thickness stage, otherwise they break by rubbing each other at a later stage and create complications. Secondly, if the center is closed, the fruits produced are of poor quality having less coloration in the absence of sufficient sunlight. By following the above practice and after giving proper shape to the trees, there will be much less scope for future pruning except removal of diseased, pest infested or dried shoots/wood.

More importantly, the few fruits set in a tree's first years of fruiting should be removed to speed up tree development.

Interculture. Interculture in orchards is necessary for the proper upkeep of any mango orchard. The removal of weeds not only avoids the competition for essential nutrients but also creates better physical soil environment for plant growth, particularly root development. It also helps in water movement in soil and in controlling some of the insect pests. Moreover, it ensures proper incorporation of the applied plant nutrients in soil and reduces their loss.

Frequency and the time of interculture operations vary with age of the orchard and existence of intercrops. Immediately after planting the mango, the weed problem may not exist, but it is advisable to break the crust with hand hoe each time after 10 to 15 irrigations. However, subsequent hoeing may be done depending on weed growth in the basin. If the intercrops are not being raised in the pre-bearing stage due to some reasons, the area between the basins should be ploughed at least three times a year, (i.e., pre-monsoon, post-monsoon and in the last week of November). Interculture operations are equally important for the bearing mango orchards. First ploughing should be done before the onset of rains. This will help in checking run-off losses and facilitate maximum retention of water in the soil. Orchard may be ploughed again after the rainy season is over in order to suppress weed growth and to break capillaries. Third ploughing may be done in the last week of November or first week of December to keep in check the proliferation of other pests/insects.

Pruning. Healthy trees require little pruning, although pruning to stimulate new growth promotes uniform annual bearing. Removing some flower clusters during a heavy bloom year may also alleviate alternate bearing. Sap and debris can cause severe dermatitis. It is best to avoid burning prunings or litter.

Developing trees should be trained to eliminate low branches less than 3 feet from the ground, leaving three to four main branches on the trunk at different heights.. Pruning of well-formed older trees is usually confined to removal of dead branches. Pruning is preferably done after fruiting, before a growth flush occurs. Pruning can also be done to restrict tree size for small yards/orchards or when more than 51 trees per hectare are planted.

Some delay in flowering can be expected from new growth produced in response to pruning.

As the tree grows older, it may be hedged and topped to control size. This is done in the summer after harvest, and if light, does not impact next year's crop since fruit are borne terminally on growth flushes that occur after pruning. Severe pruning will decrease fruiting the following year, however.

Irrigation. Amount and frequency of irrigation depends upon the type of soil, prevailing climatic conditions, especially rainfall to be given and its distribution and age of trees. No irrigation is required during the monsoon months unless there are long spells of drought. Irrigation should start when the weather warms. Continue every one to two weeks, more often in light soils, nearly continuously in areas where soil water retention is low. Irrigation may be discontinued when rains are sufficient to maintain soil moisture.

During the first year when the plants are very young with shallow root system, they should be watered every 2 to 3 days in the dry season. Trees in the age group of 2 to 5 years should be irrigated at 4 to 5 days interval. The irrigation interval could be increased to 10 to 15 days for 5 to 8 years old plants during dry season. Although hot, dry weather is favorable to fruit development, supplementary irrigation between flowering and harvest is advisable for good yields. When trees are in full bearing stage, generally 2 to 3 irrigation are given after the fruit set. Irrigation should be given at 50 percent field capacity. After harvesting, watering is then increased after one to two months to initiate a new bloom and growth cycle.

Generally, intercrops are grown during the early years of plantation and hence frequency and method of irrigation has to be adjusted accordingly. It is advisable to irrigate the mango plants in basins around them, which can be connected in series or to the irrigation channel in the centre of rows. The intercrops need to be irrigated independently as per their specific requirements. In mono-cropping of mango, basin irrigation is preferable with a view to economize water use.

Fertilization. Soil fertility has a direct effect on all aspects of crop growth and development. In some cases, post-harvest disorders can be linked directly to the deficiency of a particular mineral, but often other environmental factors such as water stress are involved. "Spongy tissue" symptoms in mango have been linked to mineral deficiency and copper and iron deficiencies cause abnormal peel development in citrus fruits.

Nutrient uptake in mango is from large volume of soils. Therefore, it is able to sustain growth even in low fertility soils. However, its efficient management involves the replenishment of the nutrients used-up by the tree for its growth and maintenance, harvested produce and natural losses from soils through leaching and run off. Even the under-nourished trees can be revived by suitable supplementation of nutrients through fertilizers.

Mango trees require regular applications of nitrogen fertilizer to promote healthy growth flushes and flower production. Organic fertilizers perform best, since the trees are subject to fertilizer burn. Young trees are particularly sensitive to over-fertilizing, but respond well to fish emulsion. Sandy soils require more fertilizer than loam or clay.

Fertilizer may be a 1:1:1 or 1:2:2 N-P-K ratio formulation, such as 14-14-14 or 10-20-20 N-P-K. During tree establishment, phosphorus (P) is important for root development. Nitrogen (N) and potassium (K) are needed by bearing trees for good yields.

The idea of applying manure to fruit bearing trees is also to secure regular fruit production. Application of manure to mango plants starts right from planting operation in the orchard. First application is made at the time of filling of the pits. Fertilizer application during the first year of planting may be given as 100 g N, 50 g P2O5 and 100 g K2O per plant. The above dose should be increased every year up to 10 years in the multiple of first year's dose. Accordingly, a 10-year-old tree should receive 1 kg N, 500 g P2O5 and 1 kg K2O. This dose should continue to be applied in subsequent years also. Application of 50 kg well-decomposed organic manure should be given each four year to create proper soil physical environment. For trench application of fertilizers, 400 g each of N and K2O and 200 g of P2O5 per plant should be given.

Fertilizers may be applied in two split doses, one half immediately after the harvesting of fruits and the other half 3 to 4 months later, in both young and old orchards, followed by irrigation if there are no rains. Supplemental N and foliar application of 3 percent urea in sandy soils is recommended before flowering, when vegetative growth flushes rather than flowering occur. Slow-release fertilizer formulations are preferred, except for supplemental N applications, which should have rapid release.

The mixture of recommended dose of fertilizers should be broadcast under the canopy of plant leaving about 50 cm from tree trunk in old trees. The applied fertilizer should be incorporated well up to the dept of 15 cm soil. To increase fertilizer use efficiency, fertilizers should be applied in 25 cm wide and 25 to 30 cm deep trenches dug around the tree 2 m away from trunk.

Diseases. Mango suffers from several diseases at all stages of its life. All the parts of the plant, namely, trunk, branch, twig, leaf, petiole, flower and fruit are attacked by a number of pathogens including fungi, bacteria and algae. They cause several kinds of rot, die back, anthracnose, scab, necrosis, blotch, spots, mildew, etc. Some of these diseases like powdery mildew are of great economic importance as they cause heavy losses in mango production. Major diseases of mango and their control measures are discussed below.

Anthracnose (Colletotrichum state of Glomerella cingulata Ston, Spaull and Schrenk): The anthracnose disease is of widespread occurrence. The disease causes serious losses to young shoots, flowers and fruits under favorable climatic conditions of high humidity, frequent rains and a temperature of 24-32oC. It is also affects fruits during storage. The disease produces leaf spot, blossom blight, withertip, twig blight and fruit rot symptoms. Tender shoots and foliage are easily affected which ultimately cause “die back” of young branches. Older twigs may also be infected through wounds which in severe cases may be fatal.

Depending on the prevailing weather conditions blossom blight may vary in severity from slight to a heavy infection of the panicles. Black spots develop on panicles as well as on fruits. Severe infection destroys the entire inflorescence resulting in no setting of fruits. Young infected fruits develop black spots, shrivel and drop off. Fruits infected at mature stage carry the fungus into storage and cause considerable loss during storage, transit and marketing. The fungus perpetuates on twigs and leaves of mango or other hosts. Since the fungus has a long saprophytic survival ability on dead twigs, the diseased twigs should be pruned and burnt along with fallen leaves for reducing the inoculum potential.

Control: Trees may be sprayed twice with Bavistin (0.1%) at 15 days interval during flowering to control blossom infection. Spraying of copper fungicides (0.3%) is recommended for the control of foliar infection.

Sooty mould (Meliola mangiferae): The disease is common in the orchards where mealy bug, scale insect and hopper are not controlled efficiently. The disease in the field is recognized by the presence of a black velvety coating (i.e., sooty mould on the leaf surface). In severe cases the trees turn completely black due to the presence of mould over the entire surface of twigs and leaves. The severity of infection depends on the honey dew secretion by the above said insects. Honey dew secretions from insects sticks to the leaf surface and provide necessary medium for fungal growth. The fungus is essentially saprophytic and is non-pathogenic because it does not derive nutrients from the host tissues. Although no direct damage is caused by the fungus, the photosynthetic activity of the leaf is adversely affected due to blockage of stomata.

Control:

Pruning of affected branches and their prompt destruction prevents the spread of the disease.

Spraying of 2 per cent starch is found effective.

It could also be controlled by spray of Nottasul + Metacin + gumacasea (0.2% + 0.1% + 0.3%).

Postharvest Diseases: The mango fruit is susceptible to many postharvest diseases caused by anthracnose (C. gloeosporioides) and stem end rot (L. theobromae) during storage under ambient conditions or even at low temperature. Aspergillus rot is another postharvest disease of mango.

Control: Pre-harvest sprays of fungicides could control the diseases caused by latent infection of these fungi. Postharvest dip treatment of fruits with fungicides could also control the diseases during storage.

The following treatments are suggested:

Three sprays of carbendazim (0.1%) orthiophante-methyl (0.1%) at 15 days interval should be done in such a way that the last spray falls 15 days prior to harvest.

Postharvest dip treatment of fruits in carbendazim (0.1%) in hot water at 52+1oC for 15 minutes.

Pests. More than 492 species of insects, 17 species of mites and 26 species of nematodes have been reported to be infesting mango trees. Almost a dozen of them have been found damaging the crop to a considerable extent causing severe losses and, therefore, may be termed as major pests of mango. These are hopper, mealy bug, inflorescence midge, fruit fly, scale insect, shoot borer, leaf webber and stone weevil. Of these, insects infesting the crop during flowering and fruiting periods cause more severe damage. The insects other than those indicated above are considered as less injurious to mango crop and are placed in the category of minor pests. A brief description of the biology and control of major pests of mango is given below.

Hopper: Of all the mango pests, hopper is considered as the most serious and widespread pest. Idioscopus clypealis Lethierry, Idioscopus nitidulus (Walker) and Amritodus atkinsoni Lethierry are the most common and destructive species of hoppers which cause heavy damage to mango crop. Large number of nymphs and adult insects puncture and suck the sap of tender parts, thereby reducing the vigor of the plants. Heavy puncturing and continuous draining of the sap cause curling and drying of the infested tissue. They also damage the crop by secreting a sweet sticky substance which encourages the development of the fungus Maliola mangiferae, commonly known as sooty mould which affects adversely the photosynthetic activities of the leaves. Shade and high humidity conditions are favorable for their multiplication. Such conditions usually prevail in old, neglected and closely planted orchards. The female hoppers lay 100-200 eggs on mid rib of tender leaves, buds and inflorescence. In summers the total life cycle occupies 2-3 weeks.

Control:

Chemical: Three sprays of 0.15 per cent Carbaryl or 0.04 per cent Monocrotophos or 0.05 per cent Phosphomidon or 0.05 per cent Methyl Parathion have been found very useful in controlling the pest population. First spray should be given at the early stage of panicle formation. The second spray at full length stage of panicles but before full bloom and the third spray after the fruits are set and have attained pea stage are recommended.

Biological: Biological control agents such as the predators Mallada boninensis and Chrysopa lacciperda, the egg parasite Polynema sp. and a preparation of the fungus Beauveria bassiana are the important useful bio-agents to control this pest.

Integrated Pest Management (IPM): The continuous use of pesticides though control the pests but pose some other serious problems like killing of pollinators and natural enemies, development of resistance to insecticides and residues which are on fruits hazardous to human population. Besides, the high cost of pesticides, labor and maintenance of equipments are other limiting factors in pest control. Integrated pest management is gaining momentum to take care of these problems. To manage mango hopper pest, avoid dense planting and keep the orchard clean by regular ploughing and removal of weeds. Pruning of overcrowding and over lapping branches should be done on a regular basis. Chemical spray is to be minimized whenever necessary. The use of insect growth regulator Buprofezin (0.0125 %) is also suggested as one of the sprays.

Mealy bug: (Drosicha mangiferae) Green is the most common mealy bug and causes severe damage to mango crop throughout the country. Nymphs and adults suck the plant sap and reduce the vigor of the plant. Excessive and continuous draining of plant sap causes wilting and finally drying of infested tissue. They also secrete honey dew, a sticky substance, which encourages the development of a fungus Maliola mangiferae, termed as sooty mould.

The adult male is winged and small, female is bigger and wingless. The female, after copulation, crawl down the tree in the month of April-May and enter in the cracks in the soil for laying eggs in large numbers encased in white egg sacs. The eggs lie in diapause state in the soil till the return of the favorable conditions in the month of November - December. Just after hatching, the minute newly hatched pink to brown colored nymphs crawl up the tree. After climbing up the tree they start sucking the sap of tender plant parts. They are considered more important because they infest the crop during the flowering season and if the control measures are not taken timely, the crop may be destroyed completely.

Control:

Mechanical: Polythene (400 gauge) bands of 25 cm width fastened around the tree trunk have been found effective barrier to stop the ascent of nymphs to the trees. The band should be fastened well in advance before the hatching of eggs, i.e., around November - December.

Chemical: Application of 250 g per tree of Methyl Parathion dust 2 per cent or Aldrin dust 10 per cent in the soil around the trunk kills the newly hatched nymphs which come in contact with the chemical. Spraying of 0.05 per cent Monocrotophos or 0.2 per cent Carbaryl or 0.05 per cent Methyl Parathion have been found useful in controlling early instar nymphs of the mealy bug.

Biological: Menochilus sexmaculatus, Rodolia fumida and Sumnius renardi are important predators in controlling the nymphs. The entomogenous fungus Beauveria bassiana is found to be an effective bio-agent in controlling the nymphs of the mealy bug.

Integrated Pest Management (IPM): The IPM schedule of mealy bug is very important and useful if timely operations are done. Flooding of orchards with water in the month of October kills the eggs. Ploughing the orchards in the month of November exposes the eggs to the sun’s heat. In the middle of December, 400 gauge alkathene sheet of 25 cm width may be fastened to the tree trunk besides raking the soil around the tree trunk and mixing of 2 per cent Methyl Parathion dust. The dust may also be sprinkled below the atkathene band on the tree. The congregated nymphs below the band may be killed by any of the suggested insecticides. The above IPM schedule holds promise to control the mealy bug but the spores of the fungus Beauveria bassiana will further ensure the reduction of the pest population.

Fruitfly: The oriental fruitfly is one of the most serious pests of mango in the country which has created problem in the export of fresh fruits. Daccus dorsalis, D. zonatus and D. correctus are the most common fruitflies which cause serious damage to mature mango fruits. The adult flies are dark brown in color and measure 7 mm in length and 4 mm across the wings. The females have tapering abdomen which ends in an ovipositor. The female punctures the outer wall of the mature fruits with the help of its pointed ovipositor and insert eggs in small clusters inside the mesocarp of mature fruits. After hatching, the larva feeds on the pulp of the fruit which appears normal from outside, but drops down finally. The mature maggots fall down into the soil for pupation. The emergence of fruitfly starts from March onwards and the maximum population is recorded during April-May which coincides with fruit maturity. The population declines slowly from June to July after which it is non-existent up to March.

Control:

Chemical: The adult fruitflies can be controlled by bait sprays of carbaryl (0.2%) + protein hydrolysate (0.1%) or molasses starting at pre-oviposition stage (first week of April), repeated once after 21 days. Another method to control these flies is to hang traps containing a 100 ml water emulsion of methyl euginol (0.1%) + Malathion (0.1%) during fruiting (April to May). About 10 such traps are sufficient for one hectare of orchard.

Integrated pest management (IPM)

Collection and proper disposal of the infested and dropped fruits.

Ploughing the orchards and exposing the diapausing pupae to sun’s heat. Releasing of parasite and predator during December to February are helpful in reducing the pest population.

Monitoring and destruction of emerging adult with methyl euginol traps.

Early harvesting of mature fruits.

Selective and need based bait spray.

Hot water treatment or vapor heat treatment (VHT) of fruits before storage and ripening for killing the larvae.

Scale insects: Scale insects are considered serious pest on mango in certain parts of the country. Pulvinaria polygonata, Aspidiatus destructor, Ceroplastis sp. and Rastococus sp. are some of the most common scale insects infesting mango crop. The nymphs and adult scales suck the sap of the leaves and other tender parts and reduce the vigor of the plants. They also secrete honeydew which encourages the development of sooty mould on leaves and other tender parts of the mango plant. In case of severe scale infestation, growth and fruit bearing capacity of the tree is affected adversely.

Control: Pruning of the heavily infested plant parts and their immediate destruction followed by two sprays of Monocrotophos (0.04 %) or Diazinon (0.04 %) or Dimethoate (0.06 %) at an interval of 20 days have been found very effective in controlling the scale population.

Shoot borer (Chlumetia transversa) : Larvae of this moth bore into the young shoot resulting in dropping of leaves and wilting of shoots. Larvae also bore into the inflorescence stalk. The adult moths are shining grey in color and measure about 17.5 mm with expanded wings. Hind wings are light in color. Female moths lay eggs on tender leaves. After hatching, young larvae enter the midrib of leaves and then enter into young shoots through the growing points by tunneling downwards. The full grown larva is dark pink in color with dirty spots and measures about 22 mm in length. There are four overlapping generations of the pest in a year and it overwinters in pupal stage.

Control: The attacked shoots may be clipped off and destroyed. Spraying of Carbaryl (0.2%) or Quinalphos (0.05%) or Monocrotophos (0.04%) at fortnightly intervals from the commencement of new flush gives effective control of the pest. A total of 2-3 sprays may be done depending on the intensity of infestation.

Stem borer (Batocera rufomaculata): Stem borer attacks a variety of fruit trees including mango. Damage is caused by the grub of this beetle as it feeds inside the stems boring upward resulting in drying of branches and in severe cases attained stem also dies. Adult beetles, 35-50 mm in size, are stout and grayish brown in color with dark brown and black spots. Eggs are laid either in the slits of tree trunk or in the cavities in main branches and stems covered with a viscous fluid. Full grown grubs are cream colored with dark brown head and 90 x 20 mm in size. Pupation takes place within the stem. Beetle emerges in July-August. There is only one generation of the pest in a year.

Control: The pest can be effectively controlled by following the recommendations given for the control of bark eating caterpillar.

Stone weevil (Sternochetus mangiferae): This insect is widely distributed in the tropics. Female lays eggs on the epicarp of partially developed fruits or under the rind of ripening fruits. Newly emerged grubs bore through the pulp, feed on seed coat and later cause damage to cotyledons. Pupation takes place inside the seed. Discoloration of the pulp adjacent to the affected portion has been observed.

Eggs are minute and white in color. Adult weevils are 5 to 8 mm long, stout and dark brown in color. Life-cycle is completed in 40 to 50 days. Adults hibernate until the next fruiting season. There is only one generation in a year.

Control:

Destroying the affected fruits and exposing the hibernating weevils by digging the soil

Spraying the trees with Fenthion (0.01%)

Disorders

Mango malformation: The malformed panicles remain unproductive and are characterized by a compact mass of male flowers, greenish in color and stunted in growth. The main and secondary rachis are thick and short and bear flowers with relatively larger bracts, sepals and petals as compared to normal flowers. The malformed panicles remain intact on the trees for a considerable period. Though research efforts made have not been able to ascertain its etiology, the complexity of the disorder is attributed cultural practices, nutritional, to many factors like, mites, fungal, viral, etc. hormonal imbalance. The exact cause and control of the malady is yet to be established. However, some remedial measures are recommended as follows:

Pruning of shoots bearing malformed panicles

Deblossoming of early emerged / infested panicles.

Biennial bearing: The term biennial, alternate or irregular bearing generally signifies the tendency of mango trees to bear a heavy crop in one year (On year) and very little or no crop in the succeeding year (Off year). Most of the commercial varieties in the Philippines biennial bearers. When a tree produces heavy crop in one season, it gets exhausted nutritionally and is unable to put forth new flush thereby failing to yield in the following season. The problem has been attributed to the causes like genetical, physiological, environmental and nutritional factors. For overcoming biennial bearing, deblossoming is recommended to reduce the crop load in the “On year” such that it is balanced in the “Off year”. Proper maintenance of orchard by way of effectively controlling pests and diseases and regular cultural operations may also result in better performance of the tree every year. Soil application of Paclobutrazol (PP333) or @ 4 - 5 g per tree in the month of September resulted in early flowering with higher fruit set and yield. It may be applied every year for regular fruiting, particularly in young trees. The time of application may vary according to fruit bud differentiation.

Fruit drop: Despite high fruit set initially, the ultimate retention is quite low in mango. The intensity of fruit drop, varies from variety to variety. The fruit drop is more or less a continuous process and can be classified into three groups: (i) Pinhead drop, (ii) Post-setting drop and (iii) March-month drop. The fruit drop in the first two groups are insignificant compared to the third group which affects the final yield significantly and needs more attention. Embryo abortion, climatic factors, disturbed water relation, lack of nutrition, disease, pest and hormonal imbalances are the major factors that lead to fruit drop. The foliar application of Alary (B-nine) @ 100 ppm or NAA 20 ppm at pea stage of fruit was found effective in controlling fruit drop in mango.

Clustering disorder in mango: A fruiting disorder is characterized by the development of fruitlets in clusters at the tip of the panicles. Such fruits do not grow beyond pea or marble stage and drop down after a month or so of fruit set. These fruits do not contain seeds when they are cut open. The disorder seems to be due to lack of pollination / fertilization which may be attributed to many reasons. Among them, absence of sufficient population of pollinators in the orchards is the major reason. The other reasons causing the disorder are old and overcrowding of trees, indiscriminate spraying against pests and diseases, use of synthetic pyrethroids for spraying, and bad weather during flowering. Some of the remedial measures are suggested below:

Insecticides should not be sprayed at full bloom to avoid killing of pollinators.

Pests and diseases should be controlled in time by spraying the recommended pesticides only.

Introduction of beehives in the orchards during flowering season for increasing the number of pollinators.

Pruning of old trees may be done to open the canopy.

Spraying of 300 ppm NAA may be done

Pollination. The pollen grains are of variable shapes, with the size varying from 20 to 35 micron. Small amounts of pollen are produced in mango. The grains of pollen are sphaeroidal to prolate sphaeroidal, radially symmetrical, subangular in polar view, isopolar, with a few giant triploid ones of up to 50 micron. Further they are 3-monocolporate, goniotreme, sides convex-subprolate; apertures equidistant and zonal with ecto-aperture (colpus) extends slit-like from pole to pole.

Mangoes are considered self-fertile and do not require pollinizers, but research indicates that some cultivars are self-unfruitful or at least benefit from cross-pollination. Fruit set is generally just a few percent, with an average of only one mango borne per panicle. The pollen incorrectly is said to cause eye irritation and dermatitis; there is almost no air-borne pollen since it is heavy and adherent. The irritation probably results from volatile, irritating oils. Pollination is achieved by wild insects, and to a lesser extent, honey bees.

There is no indication that to place colonies of honey bees in mango groves has become an accepted practice; however, the chances are likely that such bee usage is needed today much more so than when his studies were made. The evidence is quite strong that concentration of colonies of honeybees within the mango grove would result in increased floral visitation and possibly more stabilized set of fruit, particularly in some years. The mango flowers do not appear to be overly attractive to honey bees and they tend to open in large numbers at a time of year when many other flowers are also available, so visitation in commercial groves is likely to be far below that necessary for maximum floral visitation. If such is the case, a heavy concentration of colonies in the grove, possibly three to six per acre, may be necessary to obtain maximum fruit set.

Harvest, Post Harvest and Handling. The mango is the apple of the tropics, and one of the most commonly eaten fruits in tropical countries around the world. To ensure that mangoes can be commercially distributed, proper harvesting and handling procedures must strictly be followed to maintain the quality and freshness of the fruit.

Fruit Harvest: Mango fruit matures in 100 to 150 days after flowering. The fruit will have the best flavor if allowed to ripen on the tree. Ripening fruit turns the characteristic color of the variety and begins to soften to the touch. Commercial marketability requires 13% dissolved solids (sugars). When the first fruit shows color on tree, all of that size fruit or larger may be removed; repeat when remaining fruit colors. Do not store below 50° F. The fruit ripens best if placed stem end down in trays at room temperature and covered with a dampened cloth to avoid shriveling. Mangoes grown in the Visayas and Mindanao region ripen from September to January and mangoes from the Luzon region are harvested starting December to May, due to weather conditions.

Maturity: Color change from green to yellow, and the development of "shoulders" on the stem end of the fruit are the best indicators of maturity. Also, the fruit flesh turns from white to yellow starting at the endocarp and progressing outward to the skin during maturation. When the flesh is yellow to half that distance, the fruit can be harvested and will ripen normally off-tree. Fruit are not ripe at this stage, but picked firm to withstand shipment. If picked before this stage, flavor never develops and fruit are more susceptible to chilling injury and hot water damage during post-harvest fruit fly control. If fruit are left on tree until ripe, they often develop physiological breakdown termed "soft nose", "jelly seed", or "spongy tissue". Fruit removal force may also be assessed by individual pickers to determine ripeness.

Harvest Method: Mangoes are hand-harvested, simply by snapping-off fruits from peduncles in less-developed plantings, or by clipping peduncles 4 inches above the fruit when intended for export. This allows the milky, toxic latex to ooze from the stem without touching the fruit surface. Pickers use poles with cloth bags at the end to reach fruit high in the tree, or ladders and hydraulic lifts in developed countries.

Post Harvest Handling: Stems are trimmed to 1/4" prior to packing in 12 kg. boxes containing 8-20 fruits, depending on size. Fruit are culled by hand, removing diseased and off-grade fruit. In countries where fruit flies are endemic, fruit are dipped in hot water for fruit fly and anthracnose control. Hot air treatments can be used to meet export requirements as well. Resins left on fruits cause black lesions which may lead to rot.

Curing is carried out on immature fruit after harvest to allow quality development. Fruits are stored for 15 days at 70 F and RH of 85-90%. Ethylene is often supplied in more sophisticated operations to accelerate color development (by 3-8 days) and allow more uniform ripening.

Mangoes are subject to chilling injury, and must not be stored at <55°F. Storage life is only 2-3 weeks under optimal conditions.

Young Tree Establishment. Newly planted trees should be watered two or three times the first week, then once or twice per week for several weeks. Simply fill the water basin and let the water soak in. The water ring will gradually erode away over four to six months, at which time the tree can be considered established.

Delay fertilization until new growth occurs after planting, then apply monthly. Scatter the fertilizer on the ground under the tree and promptly water thoroughly. Using ammonium sulfate (21-0-0), use one half cup monthly in the first year, one cup per month in the second and two cups monthly in the third year. For other fertilizer analyses, adjust the rate accordingly.

All lawn grass and weeds should be eliminated for several feet around the young mango, as the tree cannot compete for water and nutrients until it is much larger. As the tree grows, widen the grass-free area beyond the canopy. Organic mulches are excellent for mango trees.

No pruning or training should be necessary except to remove deadwood.

Mature Tree Care. Cultural practices are designed to maintain good growth and production. Irrigation, nutrition, and weed and grass control are the major practices in mature mango tree care.

Irrigation is the same as for other established fruit and nut trees--water slowly, deeply and thoroughly. Repeat as needed, based on soil type and prevailing weather. Weekly soakings during the summer are more than adequate.

Fertilization, using 21-0-0, should be at the rate of one to two cups per inch of trunk diameter per year, split into equal applications in June and December. Simply scatter the fertilizer on the soil surface under the tree, then water thoroughly.

Weed and grass control under the tree is desirable to reduce competition and can be easily maintained by use of organic mulch replenished as necessary.

The only pruning necessary is to remove dead or damaged branches, which will occur following major freezes unless excellent cold protection methods are practiced. Then, pruning should be delayed until the extent of freeze damage can be ascertained.